Mobile carts may be used to transport heavy items, such as high pressure cylinders or liquid gas canisters. Some mobile carts have wheels for easy transport, but the wheels are always deployed. This may lead to instability, since the cart can always roll. Other mobile carts may have retractable wheels. But in order to secure the wheels in a retracted or deployed position, securing pins must be manually positioned and secured within securing pin holes. The process of manually removing or replacing the securing pins within the securing pin holes may be extremely time consuming. Furthermore, if the securing pins are misplaced, then the wheels may not be held properly in place. It would thus be desirable to provide a mobile cart with a retractable wheel assembly that did not require the use of securing pins and that allowed for quick deployment and retraction of the wheels.